The Seattle Seahawks announced earlier this week that they had reached a multiyear extension with center Max Unger, a 2009 second-round pick of the previous coaching/front office regime who the current regime had identified as a "core leader" on offense.

Terms were not disclosed, but the deal was expected to make Unger among the league's highest-paid centers in the NFL...and it has.

According to a source with knowledge of the contract, Unger's four-year extension is worth $24.935 million, a $6.233 million per-year average that ranks fourth among NFL centers behind Ryan Kalil, Nick Mangold and Chris Myers. Overall, Unger will make just over $25.5 million over the next five seasons, and the $8 million he will earn this season is second only to the $10.5 million Myers will make in the first season of his four-year, $25 million contract with the Houston Texans.

Not a bad haul for a player with just 32 NFL starts, including less than 20 at the center position.

Slated to earn $565,000 in base salary in the fourth and final year of a $3.214 million rookie contract, Unger received a $5.5 million signing bonus while his base salary has increased to a fully guaranteed $2.5 million for the upcoming season. Unger will earn $4 million in base salary in 2013, $3.5 million of which is fully guaranteed, before earning $4.5 million (non-guaranteed) in both 2014 and 2015, and $4.25 million in base salary with a $250,000 roster bonus in 2016. Undisclosed base salary escalators are available from 2013-16.

Unger's cap number has gone from $934,500 to $3.9695 million for 2012 and will increase to $5.1 million in 2013 before holding steady at $5.6 million in each of the final three seasons of the contract.